1. Field of the Invention
This invention relates to a multi-component curable composition which is reactive upon admixing of the components and which comprises:
(i) an acrylic polymer having acetoacetoxy functionality; and PA1 (ii) an acetoacetoxy functional derivative of a low molecular weight polyol; and PA1 (iii) a crosslinking component comprising at least one imine functional compound having an average of at least two imine groups per molecule which are reactive with acetoacetoxy functionality; and PA1 (iv) optionally, a polyamine having an average of at least two primary amine groups per molecule. PA1 (a) a first component comprising: PA1 (b) a crosslinking component comprising at least one imine functional compound. PA1 (i) esters of acrylic, methacrylic, crotonic, tiglic, or other unsaturated acids such as: methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, ethylhexyl acrylate, amyl acrylate, 3,5,5-trimethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isobornyl methacrylate, dimethylaminoethyl methacrylate, ethyl tiglate, methyl crotonate, ethyl crotonate, etc.; PA1 (ii) vinyl compounds such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl m-chlorobenzoate, vinyl p-methoxybenzoate, vinyl alpha-chloroacetate, vinyl toluene, vinyl chloride, etc.; PA1 (iii) styrene-based materials such as styrene, alpha-methyl styrene, alpha-ethyl styrene, alpha-bromo styrene, 2,6-dichlorostyrene, etc.; PA1 (iv) allyl compounds such as allyl chloride, allyl acetate, allyl benzoate, allyl methacrylate, etc.; PA1 (v) other copolymerizable unsaturated monomers such as acrylic acid, methacrylic acid, 2-hydroxy ethyl acrylate, acrylonitrile, methacrylonitrile, dimethyl maleate, isopropenyl acetate, isopropenyl isobutyrate, acrylamide, methacrylamide, and dienes such as 1,3-butadiene, etc. PA1 wherein n is 1 to 30, and preferably n is 1 to 5; R.sub.1 and R.sub.2 are hydrogen, an alkyl, aryl, cycloaliphatic, or substituted alkyl, aryl, or cycloaliphatic group; and R.sub.1 and R.sub.2 may be the same or different; and R.sub.3 is an aliphatic, aromatic, arylaliphatic or cycloaliphatic group which may also contain heteroatoms such as O, N, S, or Si.
The curable compositions of this invention are especially useful as coatings, particularly primers. The reactive coatings of this invention can be cured at room temperature or force dried at temperatures ranging up to about 350.degree. F. The combination of acetoacetoxy functional materials and imine functional materials provide fast reacting, durable coatings having excellent adhesion.
2. Description of the Prior Art
The use of acetoacetoxy functional materials in Michael-type reactions is known in the art. For example, U.S. Pat. No. 3,668,183 teaches the reaction of polyacetoacetates and polyimines. European Patent Application 744,450 teaches reactive compositions of acetoacetates and multi-functional amines.
The prior art has not, however, taught the combination of an acetoacetoxy functional acrylic polymer and an acetoacetoxy functional derivative of a low molecular weight polyol, and an imine functional material and, optionally, a polyamine to provide low temperature curing coatings having excellent durability, adhesion and performance.